AU: When reporting error to Omaha, also notify crash reporter

TEST=tested on device: made sure error triggered it, non error didn't
trigger it.
BUG=10739

Review URL: http://codereview.chromium.org/6100006

Change-Id: Ifc742916c15694e23ccb3b0c48b9ecacd44a2fd9
diff --git a/update_attempter.cc b/update_attempter.cc
index 3ea1c18..a63a1e8 100644
--- a/update_attempter.cc
+++ b/update_attempter.cc
@@ -282,6 +282,8 @@
 
   if (status_ == UPDATE_STATUS_REPORTING_ERROR_EVENT) {
     LOG(INFO) << "Error event sent.";
+    // Tell crash reporter there was a problem.
+    utils::ScheduleCrashReporterUpload();
     SetStatusAndNotify(UPDATE_STATUS_IDLE);
     return;
   }